Add websocket command to set preferred thread dataset (#89700)

tests/components/thread/test_websocket_api.py

@@ -197,6 +197,56 @@ async def test_list_get_dataset(
     assert msg["error"] == {"code": "not_found", "message": "unknown dataset"}
 
 
+async def test_set_preferred_dataset(
+    hass: HomeAssistant, hass_ws_client: WebSocketGenerator
+) -> None:
+    """Test we set a dataset as default."""
+    assert await async_setup_component(hass, DOMAIN, {})
+    await hass.async_block_till_done()
+
+    datasets = [
+        {"source": "Google", "tlv": DATASET_1},
+        {"source": "Multipan", "tlv": DATASET_2},
+        {"source": "🎅", "tlv": DATASET_3},
+    ]
+    for dataset in datasets:
+        await dataset_store.async_add_dataset(hass, dataset["source"], dataset["tlv"])
+
+    store = await dataset_store.async_get_store(hass)
+
+    for dataset in store.datasets.values():
+        if dataset.source == "🎅":
+            dataset_3 = dataset
+
+    client = await hass_ws_client(hass)
+
+    await client.send_json(
+        {"id": 1, "type": "thread/set_preferred_dataset", "dataset_id": dataset_3.id}
+    )
+    msg = await client.receive_json()
+    assert msg["success"]
+    assert msg["result"] is None
+
+    store = await dataset_store.async_get_store(hass)
+    assert store.preferred_dataset == dataset_3.id
+
+
+async def test_set_preferred_dataset_wrong_id(
+    hass: HomeAssistant, hass_ws_client: WebSocketGenerator
+) -> None:
+    """Test we set a dataset as default."""
+    assert await async_setup_component(hass, DOMAIN, {})
+    await hass.async_block_till_done()
+
+    client = await hass_ws_client(hass)
+
+    await client.send_json(
+        {"id": 1, "type": "thread/set_preferred_dataset", "dataset_id": "don_t_exist"}
+    )
+    msg = await client.receive_json()
+    assert msg["error"]["code"] == "not_found"
+
+
 async def test_discover_routers(
     hass: HomeAssistant, hass_ws_client: WebSocketGenerator, mock_async_zeroconf: None
 ) -> None: